斜拉索‒双阻尼器系统多模态减振理论与试验研究

Theoretical and Experimental Studies on Multimode Vibration Mitigation of Cable with Two Dampers

摘要:

建立拉索?双阻尼器系统精细化分析模型（阻尼器Ⅰ为黏弹性阻尼器（Kelvin-Voigt模型），阻尼器Ⅱ为高阻尼橡胶（HDR）阻尼器），并推导了拉索?双阻尼器系统的一般分析公式。以某斜拉桥的拉索为例，对安装双阻尼器的拉索和仅安装阻尼器Ⅰ的拉索进行长期监测，结果表明双阻尼器方案能有效抑制仅安装阻尼器Ⅰ拉索的高阶涡振。实索试验结果表明：仅安装阻尼器Ⅰ和安装双阻尼器时拉索较低阶模态阻尼的测量值与理论分析值基本吻合；同端安装阻尼器Ⅱ对阻尼器Ⅰ提升拉索低阶模态阻尼的效果有削弱作用，拉索前几阶模态受到的影响较为明显。此外，理论分析发现，阻尼器Ⅰ的刚度对阻尼器Ⅱ提升拉索高阶模态阻尼的效果有提升作用。

Abstract:

A refined model of the shallow cable attached with two dampers（cable-two dampers） ， where one damper （damper Ⅰ） is a viscoelastic damper and the other one （damper Ⅱ） is a high damping rubber （HDR） damper， is established. General frequency formulas of the cable-two dampers system are then obtained. Two long cables of an existing cable-stayed bridge are used for experimental study and field monitoring. The long-term vibration monitoring of the cables with two dampers and with only one viscous-shear damper respectively has shown that the vortex-induced vibrations experienced by the cable only with the viscoelastic damper are successfully mitigated by the additional HDR damper. Besides， field tests on the cable damping before and after the installation of the HDR damper have indicated that the achievable damping ratios for the low-order modes of the cable are consistent with the corresponding theoretical estimates； meanwhile， the existence of the HDR damper somehow decreases the cable damping in low-order modes supplemented by the viscoelastic damper， and the reduction effect is more significant for the first several modes. Moreover， it is theoretically found that the stiffness of the viscoelastic damper helps improve the damping effect of the HDR damper on the high-order modes of the cable.